Square.



No. 680,815. Patented Aug. 2o, mol.

L. s. WARREN.

SQUARE.

(Application filed Dec. 31, 1900.,

(No Modal.)

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SPECIFICATION forming part of Letters Patent No. 680,815, dated August20, 1901.

Application filed December 31, 1900. Serial No. 41,571. (No model.)

To all whom, t may concern/.-

Be it known that I, LARoY S. STARRETT, of Athol, in the county ofWorcester and State of Massachusetts, have invented certain new anduseful Improvements in Squares,of which the following is aspecification.

The object of this invention is not only to cheapen the process ofmakinga trisquare by using two detachable. straight edges or rules,which are more easily made than one formed at a right angle in onepiece, but also to provide for the use of mechanics a folding steel orknockdown square, which is vastly more compact in the tool-chest thanthe ordinary rigid squares. By my invention the two blades, usuallyformed integral and standing permanently at right angles to each other,are so joined together that they may be disconnected and laid dat oneupon the other for compact storage, and yet when required for use theymay be quickly united by a single stud, holding them exactlyperpendicularand with an exceedingly stiff joint. In the best form of myimproved square the edge of the shorter blade is held in firm contactwith the end of the longer one by means of two projecting plates orlinks secured on opposite sides of the shorter blade and extending eachside of the longer one over the joint Where the two blades meet to aperforation in the longer member, which registers with perforations insaid links and by an eccentric stud occupying such perforations andnicked end- Wise, like a screw, to provide for its partial rotation. Theends of said stud are cylindrical and iill the perforations of differentsizes in said links, while the intermediate eccentric porrion iills theperforation in the longer blade, so that partial rotation by means of ascrew-driver applied to the nicked head draws the blades into closecontact or frees them. When loosened, the stud may be removed and theblades disconnected. These connecting-links are preferably pivoted tothe shorter blade, so that they can swing into parallelism with it andnot protrude at all when the tool is to be folded; but they may beformed as rigid plates extending permanently from the end of said bladeand have the edge of the longer one secured thereto by said eccentricstud. The links may project from the longer blade, if preferred.

In the drawings, Figure l is a plan of my improved square, showing theparts assembled for use. Fig. 2 represents the two blades detached. Fig.3 is an enlarged section of the tool on line 3 3, Fig. 1. Figs. Lland 5are end and perspective views of the eccentric stud enlarged.

A and B represent, respectively, the long and short blades of my jointedsquare, made of equal thinkness and preferably of thin steel andgraduated along each margin of both sides. The edges are parallel andthe ends at right angles thereto, as usual.

C C represent two flat plates or links secured on opposite sides of oneblade, preferably the shorter one, B, at one end, and proj ectin g eachside of the other blade at its end. Perforations c are formed throughthe free end of said links, registering with a perforation d through theblade which they embrace. Through these perforations, which are ofdifferent sizes, the eccentric stud D E F passes, its nicked headoccupying the larger and its tip F the smaller perforation in the links,while its intermediate eccentric portion E lls the aperture a in theblade A. These parts are so proportioned and the perforations so locatedthat less than half a revolution of the stud D E F will tighten theblades into a rigid union, as in Figs. l and 3, or loosen them, so thatthe stud may drop out and the parts be detached for folding, as in Figs.2, 4., and 5.

The links are shown in Figs. l and 3 as connected by pivots G to andextending transversely from the blade B, which is the preferableconstruction; but they may extend rig* idly beyond the end of said bladein the position shown in Fig. 2. The pivot G is preferably enlargedcentrally, as shown in Fig. 3. The edge graduation of one blade may becontinued across the end of the other, as indicated in Fig. 1.

I claim as my inventionl. In a separable square, the detachable blades AB in combination with the links C O projecting from one blade and havingterminal perforations c and with the eccentric stud D F. F occupying theperforations in said links and illing the aperture in the other blade,interposed between them, substantially as set forth.

IOO

2. The improved 'square herein described, loosened for separation, bypartial rotation comprising the blades A B, the links C C pivof suchstud, substantially as setforth. 1o oted to and projecting from one ofsaid blades, In testimony whereof I have affixed my sigand theconnectng-studhaving a cylindrical nature in presence of two Witnesses.

5 head and tip occupying` perforations in said LAROY S. STARRETTi links,and an intermediate eccentric portion Witnesses: l filling a perforationin the other blade, the FRANK E. WING, parts being so located as to betightened, and E. P. BARRUS.

